The contrary intracellular and extracellular functions of PEDF in HCC development

Abstract Pigment epithelium-derived factor (PEDF), a classic angiogenic inhibitor, has been reported to function as a tumor suppression protein and to downregulate in many types of solid tumors. However, the expression level of PEDF and its role in hepatocellular carcinoma (HCC) are contradictory. The present study investigates the expression and different activities of secreted and intracellular PEDF during HCC development, as well as the underlying mechanism of PEDF on HCC lipid disorders. We found that PEDF had no association with patients’ prognosis, although PEDF was highly expressed and inhibited angiogenesis in HCC tumor tissues. The animal experiments indicated that full-length PEDF exhibited equalizing effects on tumor growth activation and tumor angiogenesis inhibition in the late stage of HCC progression. Importantly, the pro-tumor activity was mediated by the intracellular PEDF, which causes accumulation of free fatty acids (FFAs) in vivo and in vitro. Based on the correlation analysis of PEDF and lipid metabolic indexes in human HCC tissues, we demonstrated that the intracellular PEDF led to the accumulation of FFA and eventually promoted HCC cell growth by inhibiting the activation of AMPK via ubiquitin–proteasome-mediated degradation, which causes increased de novo fatty acid synthesis and decreased FFA oxidation. Our findings revealed why elevated PEDF did not improve the patients’ prognosis as the offsetting intracellular and extracellular activities. This study will lead to a comprehensive understanding of the diverse role of PEDF in HCC and provide a new selective strategy by supplement of extracellular PEDF and downregulation of intracellular PEDF for the prevention and treatment of liver cancer.

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USP22-dependent accumulation of lipidomes drives hepatocellular carcinoma progression by stabilizing PPARγ

10.21203/rs.3.rs-82450/v1 ◽

2020 ◽

Author(s):

Zhen Ning ◽

Xin Guo ◽

Xiaolong Liu ◽

Chang Lu ◽

Aman Wang ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Fatty Acid ◽

Molecular Mechanism ◽

Fatty Acid Synthesis ◽

De Novo ◽

Acid Synthesis ◽

Specific Protease ◽

Pparγ Expression

Abstract Elevated de novo lipogenesis (DNL) is considered to be a crucial factor in hepatocellular carcinoma (HCC) development. However, the molecular mechanism for its occurrence in HCC is still unclear. Herein, we identified ubiquitin-specific protease 22 (USP22) as a key regulator for de novo fatty acid synthesis, which directly interacts with, deubiquitinates and stabilizes PPARγ through K48-linked deubiquitination, and in turn, this stabilization increases ACC and ACLY transcription. In addition, we found that USP22 promoted the de novo synthesis of fatty acid labeling from glucose tracers. USP22-dysregulated de novo fatty acid synthesis contributes to HCC progression, but USP22 was functionality suppressed by inhibiting the expression of PPARγ, ACLY, or ACC in in vitro cell proliferation and in vivo tumorigenesis experiments. In HCC, USP22 expression positively correlates with PPARγ expression, and simultaneously, high expression of USP22 and PPARγ or USP22, ACC and ACLY is associated with a poor prognosis. Taken together, we identified a previously undescribed USP22-regulated lipogenesis molecular mechanism that involves the PPARγ-ACLY/ACC axis in HCC tumorigenesis and provide a rationale for therapeutic targeting of lipogenesis via USP22 inhibition.

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Modeling Human Peripheral Myelin Fully from Pluripotent Stem Cells and Immune-mediated Neuropathy In Vitro using ZIKA Virus

10.1101/2020.05.23.112748 ◽

2020 ◽

Author(s):

Fahimeh Mirakhori ◽

Cheng-Feng Qin ◽

Zhiheng Xu

Keyword(s):

Stem Cells ◽

Pluripotent Stem Cells ◽

Zika Virus ◽

De Novo ◽

Underlying Mechanism ◽

Suitable Model ◽

Zikv Infection ◽

Compound Screening

SummaryThe generation of in vitro model of human peripheral myelin development and associated disease from human pluripotent stem cells (hPSCs) has been a challenge so far. In addition, the underlying mechanism for ZIKA virus (ZIKV) infection incurred Guillain-Barré syndrome (GBS) remains unexplored due to the lack of a suitable model. Here, we report the de novo generation of a human peripheral myelination model with competent Schwann cells (SCs). Those human SCs generated from hPSCs via compound screening were capable of forming compact myelin both in vitro and in vivo. We found ZIKV infection caused GBS-like events in vitro including myelin sheath degeneration, as well as dysregulated transcriptional profile including the activated cell death pathways and cytokine production. These effects could be partially reversed by several pharmacological inhibitors. Our model therefore provides a new and robust tool for studying the pathogenic mechanisms and developing of therapeutic strategies for related neuropathies.

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De novo synthesis of fructo-oligosaccharides in leaf disks of certain Asteraceae

Canadian Journal of Botany ◽

10.1139/b72-040 ◽

1972 ◽

Vol 50 (2) ◽

pp. 295-303 ◽

Cited By ~ 19

Author(s):

K. R. Chandorkar ◽

F. W. Collins

Keyword(s):

Chain Length ◽

De Novo ◽

Close Correlation ◽

Acid Synthesis ◽

Degree Of Polymerization ◽

De Novo Synthesis ◽

The Relationship ◽

Leaf Disks

Incubation of leaf disks of certain genera of Asteraceae on phosphate-buffered, 5% sugar solutions resulted in the de novo synthesis of a homologous series of inulin-type fructosans. Fructo-oligosaccharides of degree of polymerization 3 to 21 or 22 were present in dandelion, chicory, lettuce, hawkweed, and sow thistle leaf disks after 72 h, but not in dahlia or sunflower. Synthesis occurred with media containing either fructose, glucose, or sucrose, but not with mannose or galactose. Fructosan formation began after about 36 h and continued with the sequential synthesis of homologs of increasing chain length. After 72 h, the relationship between the amount of polymer synthesized and the chain length appeared to be logarithmically biphasic, consisting of two series of exponentially decreasing values. Incubation for 120 h however, resulted in a distribution more closely resembling that found naturally in fructosan storing tissues. 14C-tracer studies showed that both the endogenous and exogenous carbohydrate sources contribute to fructosan synthesis. Fructo-oligosaccharide formation was blocked by cycloheximide, puromycin, and actinomycin D but not chloramphenicol, indicating that cytoplasmic protein and nucleic acid synthesis was required. Analysis of fructosan formation during incubation suggests a close correlation between transfructosylation mechanisms observed in vitro and the de novo synthesis of fructosans in vivo.

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DAB2IP inhibits p53 ubiquitin-mediated degradation by competitively binding to GRP75 and suppresses tumor malignancy in colon cancer

10.1101/2021.06.28.450115 ◽

2021 ◽

Author(s):

Jie Shen ◽

Shengjie Feng ◽

Jiao Deng ◽

Qingwen Huang ◽

Dayong Zhao ◽

...

Keyword(s):

Colon Cancer ◽

Animal Experiments ◽

Underlying Mechanism ◽

Dependent Manner ◽

Wild Type ◽

Vitro Assay ◽

Cell Invasiveness ◽

The Stability

Increasing evidence has shown that DAB2IP acts as a tumor suppressor and plays an inhibition role in many tumors. However, the underlying mechanism is still uncertain. Our study shows that DAB2IP is positively associated with a better prognosis in colon cancer patients with wild-type TP53 expression. In vitro assay shows that DAB2IP elicits potent tumor-suppressive effects on inhibiting cell invasiveness, colony formation and promoting cell apoptosis in wild-type TP53 colon cancer cell lines. Subsequently, DAB2IP is demonstrated to up-regulate the stability of wild-type TP53 by inhibiting its degradation in a ubiquitin-proteasome-dependent manner. Using mass spectrometry profiling, we unveil that DAB2IP and p53 could both interact with the ubiquitin ligase-related protein, GRP75. Mechanistically, DAB2IP could competitively bind with GRP75, thus reducing GRP75-mediated p53 ubiquitination and degradation. Finally, animal experiments also reveal that DAB2IP inhibits the tumor progression in vivo. In conclusion, our study presents a novel function of DAB2IP in GRP75-driven wild-type p53 degradation, which provides a new insight in DAB2IP-induced tumor suppression and provides a novel molecular aspect of the p53 pathway.

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Long Non-Coding RNA CYP4B1-PS1-001 Inhibits Proliferation and Fibrosis in Diabetic Nephropathy by Interacting with Nucleolin

Cellular Physiology and Biochemistry ◽

10.1159/000493821 ◽

2018 ◽

Vol 49 (6) ◽

pp. 2174-2187 ◽

Cited By ~ 14

Author(s):

Suyu Wang ◽

Xin Chen ◽

Min Wang ◽

Di Yao ◽

Tianyu Chen ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Rna Binding ◽

Mesangial Cells ◽

Critical Role ◽

Underlying Mechanism ◽

Non Coding Rna ◽

Ubiquitin Proteasome ◽

Long Non Coding Rna

Background/Aims: Our previous studies demonstrated that a novel long non-coding RNA, CYP4B1-PS1-001, was significantly downregulated in early diabetic nephropathy in vivo and in vitro, and CYP4B1-PS1-001 overexpression could inhibit the proliferation and fibrosis of mouse mesangial cells (MMCs). However, the underlying mechanism of the CYP4B1-PS1-001-mediated regulation of proliferation and fibrosis in diabetic nephropathy remains undetermined. Methods: RNA-protein pull-down assay, RNA-binding protein immunoprecipitation, and mass spectrometry were used to investigate CYP4B1-PS1-001 interacted with the upregulated protein nucleolin (NCL). siRNA method was applied to knockdown NCL in MMCs, the interaction between CYP4B1-PS1-001 and NCL were determined by Western blot analysis and RT-qPCR. The effect of CYP4B1-PS1-001 in the regulation of NCL was detected by cycloheximide (CHX) and ubiquitination assays. Results: We found that CYP4B1-PS1-001 interacts with NCL, and CYP4B1-PS1-001 inhibits the proliferation and fibrosis of MMCs depending on interaction with NCL. Furthermore, degradation of CYP4B1-PS1-001-associated NCL was mediated by a ubiquitin proteasome-dependent pathway. Conclusion: Our study provides evidence that CYP4B1-PS1-001 regulates the ubiquitination and degradation of NCL and thereby plays a critical role in the proliferation and fibrosis of MMCs, indicating that CYP4B1-PS1-001 and NCL may be promising prognostic biomarkers and molecular targets for the treatment of diabetic nephropathy.

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Retinoblastoma cell-derived exosomes promote angiogenesis of human vesicle endothelial cells through microRNA‐92a-3p

Cell Death and Disease ◽

10.1038/s41419-021-03986-0 ◽

2021 ◽

Vol 12 (7) ◽

Author(s):

Shuilian Chen ◽

Xi Chen ◽

Qian Luo ◽

Xuan Liu ◽

Xiao Wang ◽

...

Keyword(s):

Endothelial Cells ◽

Tumor Cells ◽

Tumor Angiogenesis ◽

Animal Experiments ◽

Tumor Development ◽

Underlying Mechanism ◽

Tube Formation ◽

Promoting Effect

AbstractExosomes derived from tumor cells play a key role in tumor development. In the present study, we identified the bioactivity of exosomes released from WERI-Rb1 retinoblastoma cells in tumor angiogenesis, as well as the underlying mechanism, through biochemical methods and animal experiments. Our in vitro data showed that exosomes could be engulfed by human vesicle endothelial cells (HUVECs), significantly promote cell viability and induce an inflammatory response in HUVECs by increasing the expression of a series of related genes, such as IL-1, IL-6, IL-8, MCP-1, VCAM1, and ICAM1. Significant increases in migration and tube formation were also observed in the HUVECs incubated with exosomes. Moreover, experiments with a nude mouse xenotransplantation model showed that exosomes injected near tumors could be strongly absorbed by tumor cells. The numbers of endothelial cells and blood vessels were significantly increased in tumor tissues treated with exosomes compared to control tissues. Furthermore, to reveal the mechanism underlying exosome-mediated angiogenesis in retinoblastoma, we analyzed the levels of 12 microRNAs in the exosomes. Specifically, our data showed that miR-92a-3p was enriched in RB exosomes. Accordingly, miR-92a-3p was increased in the HUVECs incubated with these exosomes. After treatment with a miR-92a-3p inhibitor, the promoting effect of exosomes on the migration and tube formation of HUVECs was significantly abrogated. The expression of the angiogenesis-related genes mentioned above was markedly decreased in HUVECs. Similarly, treatment with a microRNA mimic also demonstrated that miR-92a-3p was involved in the angiogenesis of HUVECs. More importantly, bioinformatics analysis predicted that Krüppel-like factor 2 (KLF2), a member of the KLF family of zinc-finger transcription factors, might be an active target of miR-92a-3p. Notably, this prediction was confirmed both in vitro and in vivo. Thus, our work suggests that exosomal miR-92a-3p is involved in tumor angiogenesis and might be a promising therapeutic candidate for retinoblastoma.

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Effects of Probiotics in the Management of Infected Chronic Wounds: From Cell Culture to Human Studies

Current Clinical Pharmacology ◽

10.2174/1574884714666191111130630 ◽

2020 ◽

Vol 15 (3) ◽

pp. 193-206

Author(s):

Brognara Lorenzo ◽

Salmaso Luca ◽

Mazzotti Antonio ◽

Di M. Alberto ◽

Faldini Cesare ◽

...

Keyword(s):

Chronic Wounds ◽

Animal Experiments ◽

Multidrug Resistant ◽

Preliminary Evidence ◽

Human Studies ◽

In Vivo Studies ◽

Resistant Bacteria ◽

Keywords Probiotics

Background: Chronic wounds are commonly associated with polymicrobial biofilm infections. In the last years, the extensive use of antibiotics has generated several antibiotic-resistant variants. To overcome this issue, alternative natural treatments have been proposed, including the use of microorganisms like probiotics. The aim of this manuscript was to review current literature concerning the application of probiotics for the treatment of infected chronic wounds. Methods: Relevant articles were searched in the Medline database using PubMed and Scholar, using the keywords “probiotics” and “wound” and “injuries”, “probiotics” and “wound” and “ulcer”, “biofilm” and “probiotics” and “wound”, “biofilm” and “ulcer” and “probiotics”, “biofilm” and “ulcer” and “probiotics”, “probiotics” and “wound”. Results: The research initially included 253 articles. After removal of duplicate studies, and selection according to specific inclusion and exclusion criteria, 19 research articles were included and reviewed, accounting for 12 in vitro, 8 in vivo studies and 2 human studies (three articles dealing with animal experiments included also in vitro testing). Most of the published studies about the effects of probiotics for the treatment of infected chronic wounds reported a partial inhibition of microbial growth, biofilm formation and quorum sensing. Discussion: The application of probiotics represents an intriguing option in the treatment of infected chronic wounds with multidrug-resistant bacteria; however, current results are difficult to compare due to the heterogeneity in methodology, laboratory techniques, and applied clinical protocols. Lactobacillus plantarum currently represents the most studied strain, showing a positive application in burns compared to guideline treatments, and an additional mean in chronic wound infections. Conclusions: Although preliminary evidence supports the use of specific strains of probiotics in certain clinical settings such as infected chronic wounds, large, long-term clinical trials are still lacking, and further research is needed.

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Perilla frutescens Leaf Extract and Fractions: Polyphenol Composition, Antioxidant, Enzymes (α-Glucosidase, Acetylcholinesterase, and Tyrosinase) Inhibitory, Anticancer, and Antidiabetic Activities

Foods ◽

10.3390/foods10020315 ◽

2021 ◽

Vol 10 (2) ◽

pp. 315

Author(s):

Zhenxing Wang ◽

Zongcai Tu ◽

Xing Xie ◽

Hao Cui ◽

Kin Weng Kong ◽

...

Keyword(s):

Ethyl Acetate ◽

Animal Experiments ◽

Ethyl Acetate Fraction ◽

The Body ◽

Total Phenolic ◽

Antioxidant Power ◽

Glycogen Accumulation ◽

Inhibitory Ability

This study aims to evaluate the bioactive components, in vitro bioactivities, and in vivo hypoglycemic effect of P. frutescens leaf, which is a traditional medicine-food homology plant. P. frutescens methanol crude extract and its fractions (petroleum ether, chloroform, ethyl acetate, n-butanol fractions, and aqueous phase residue) were prepared by ultrasound-enzyme assisted extraction and liquid–liquid extraction. Among the samples, the ethyl acetate fraction possessed the high total phenolic (440.48 μg GAE/mg DE) and flavonoid content (455.22 μg RE/mg DE), the best antioxidant activity (the DPPH radical, ABTS radical, and superoxide anion scavenging activity, and ferric reducing antioxidant power were 1.71, 1.14, 2.40, 1.29, and 2.4 times higher than that of control Vc, respectively), the most powerful α-glucosidase inhibitory ability with the IC50 value of 190.03 μg/mL which was 2.2-folds higher than control acarbose, the strongest proliferative inhibitory ability against MCF-7 and HepG2 cell with the IC50 values of 37.92 and 13.43 μg/mL, which were considerable with control cisplatin, as well as certain inhibition abilities on acetylcholinesterase and tyrosinase. HPLC analysis showed that the luteolin, rosmarinic acid, rutin, and catechin were the dominant components of the ethyl acetate fraction. Animal experiments further demonstrated that the ethyl acetate fraction could significantly decrease the serum glucose level, food, and water intake of streptozotocin-induced diabetic SD rats, increase the body weight, modulate their serum levels of TC, TG, HDL-C, and LDL-C, improve the histopathology and glycogen accumulation in liver and intestinal tissue. Taken together, P. frutescens leaf exhibits excellent hypoglycemic activity in vitro and in vivo, and could be exploited as a source of natural antidiabetic agent.

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GCH1 induces immunosuppression through metabolic reprogramming and IDO1 upregulation in triple-negative breast cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-002383 ◽

2021 ◽

Vol 9 (7) ◽

pp. e002383

Author(s):

Jin-Li Wei ◽

Si-Yu Wu ◽

Yun-Song Yang ◽

Yi Xiao ◽

Xi Jin ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Molecular Taxonomy ◽

Underlying Mechanism ◽

Metabolic Reprogramming ◽

Sequencing Data ◽

Aryl Hydrocarbon

PurposeRegulatory T cells (Tregs) heavily infiltrate triple-negative breast cancer (TNBC), and their accumulation is affected by the metabolic reprogramming in cancer cells. In the present study, we sought to identify cancer cell-intrinsic metabolic modulators correlating with Tregs infiltration in TNBC.Experimental designUsing the RNA-sequencing data from our institute (n=360) and the Molecular Taxonomy of Breast Cancer International Consortium TNBC cohort (n=320), we calculated the abundance of Tregs in each sample and evaluated the correlation between gene expression levels and Tregs infiltration. Then, in vivo and in vitro experiments were performed to verify the correlation and explore the underlying mechanism.ResultsWe revealed that GTP cyclohydrolase 1 (GCH1) expression was positively correlated with Tregs infiltration and high GCH1 expression was associated with reduced overall survival in TNBC. In vivo and in vitro experiments showed that GCH1 increased Tregs infiltration, decreased apoptosis, and elevated the programmed cell death-1 (PD-1)-positive fraction. Metabolomics analysis indicated that GCH1 overexpression reprogrammed tryptophan metabolism, resulting in L-5-hydroxytryptophan (5-HTP) accumulation in the cytoplasm accompanied by kynurenine accumulation and tryptophan reduction in the supernatant. Subsequently, aryl hydrocarbon receptor, activated by 5-HTP, bound to the promoter of indoleamine 2,3-dioxygenase 1 (IDO1) and thus enhanced the transcription of IDO1. Furthermore, the inhibition of GCH1 by 2,4-diamino-6-hydroxypyrimidine (DAHP) decreased IDO1 expression, attenuated tumor growth, and enhanced the tumor response to PD-1 blockade immunotherapy.ConclusionsTumor-cell-intrinsic GCH1 induced immunosuppression through metabolic reprogramming and IDO1 upregulation in TNBC. Inhibition of GCH1 by DAHP serves as a potential immunometabolic strategy in TNBC.

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Breakdown of Filamentous Myofibrils by the UPS–Step by Step

Biomolecules ◽

10.3390/biom11010110 ◽

2021 ◽

Vol 11 (1) ◽

pp. 110

Author(s):

Dina Aweida ◽

Shenhav Cohen

Keyword(s):

Protein Quality ◽

Protein Structures ◽

Ubiquitin Proteasome System ◽

Surface Proteins ◽

Catalytic Core ◽

Complex Protein ◽

Ubiquitin Proteasome ◽

Aaa Atpases

Protein degradation maintains cellular integrity by regulating virtually all biological processes, whereas impaired proteolysis perturbs protein quality control, and often leads to human disease. Two major proteolytic systems are responsible for protein breakdown in all cells: autophagy, which facilitates the loss of organelles, protein aggregates, and cell surface proteins; and the ubiquitin-proteasome system (UPS), which promotes degradation of mainly soluble proteins. Recent findings indicate that more complex protein structures, such as filamentous assemblies, which are not accessible to the catalytic core of the proteasome in vitro, can be efficiently degraded by this proteolytic machinery in systemic catabolic states in vivo. Mechanisms that loosen the filamentous structure seem to be activated first, hence increasing the accessibility of protein constituents to the UPS. In this review, we will discuss the mechanisms underlying the disassembly and loss of the intricate insoluble filamentous myofibrils, which are responsible for muscle contraction, and whose degradation by the UPS causes weakness and disability in aging and disease. Several lines of evidence indicate that myofibril breakdown occurs in a strictly ordered and controlled manner, and the function of AAA-ATPases is crucial for their disassembly and loss.

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